1. Field of the Invention
Embodiments of the present invention are directed toward novel compositions comprising the C26H30 hexamantane herein referred to as “cylcohexamantane.”
2. References
The following publications and patents are cited in this application as superscript numbers:
1 Lin, et al., Natural Occurrence of Tetramantane (C22H28),Pentamantane (C26H32) and Hexamantane (C30H36) in a Deep Petroleum Reservoir, Fuel, 74(10):1512-1521 (1995)
2 Alexander, et al., Purification of Hydrocarbonaceous Fractions, U.S. Pat. No. 4,952,748, issued Aug. 28, 1990
3 McKervey, Synthetic Approaches to Large Diamondoid Hydrocarbons, Tetrahedron, 36:971-992 (1980).
4 Wu, et al., High Viscosity Index Lubricant Fluid, U.S. Pat. No. 5,306,851, issued Apr. 26, 1994.
5 Chung et al., Recent Development in High-Energy Density Liquid Fuels, Energy and Fuels, 13, 641-649 (1999).
6 Sandia National Laboratories (2000), World's First Diamond Micromachines Created at Sandia, Press Release, (2/22/2000) www.Sandia.gov.
7 Balaban et al., Systematic Classification and Nomenclature of Diamondoid Hydrocarbons—I, Tetrahedron. 34, 3599-3606 (1978).
8 Chen, et al., Isolation of High Purity Diamondoid Fractions and Components, U.S. Pat. No. 5,414,189, issued May 9, 1995
All of the above publications and patents are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference in its entirety.
3. State of the Art
Hexamantanes are bridged-ring cycloalkanes. They are the hexamers of adamantane (tricyclo[3.3.1.13,7]decane) or C10H16, in which various adamantane units are face-fused. The compounds have a “diamondoid” topology, which means their carbon atom arrangement is superimposable on a fragment of the diamond lattice (FIG. 1). Hexamantanes possess six of the “diamond crystal units” and therefore, it is postulated that there are thirty-nine possible hexamantane structures. Among them, twenty-eight of the thirty-nine have the stoichiometric formula C30H36 (molecular weight 396 Daltons) and of these, six are symmetrical, having no enantiomers. Ten of the thirty-nine hexamantanes have the stoichiometric formula C29H34 (molecular weight 382 Daltons).
The remaining hexamantane (FIGS. 2 and 3) is fully condensed, has the stoichiometric formula C26H30 (molecular weight 342 Daltons), and compositions comprising this hexamantane are the subject matter of the embodiments of this invention.
Very little has been published pertaining to the hexamantanes in general, and cyclohexamantane in particular. Hexamantane compounds have not been artificially synthesized, and these compounds have been recently thought to have only a theoretical existence.1,7 Academic chemists have primarily focused research on the interplay between physical and chemical properties in the lower diamondoids such as adamantane, diamantane and triamantane. Adamantane and diamantane, for instance, have been studied to elucidate structure-activity relationships in carbocations and radicals.3 Process engineers have directed efforts toward removing lower diamondoids from hydrocarbon gas streams.2 Lower diamondoids can cause problems during the production of natural gas by solidifying in pipes and other pieces of related processing equipment.
The literature contains little information regarding the practical applications of hexamantanes. This fact is probably due to extreme difficulties encountered in their isolation and due to failed synthesis attempts. Lin and Wilk, for example, discuss the possible presence of pentamantanes in a gas condensate and further postulate that hexamantanes may also be present.1 The researchers postulate the existence of the compounds based on a mass spectrometric fragmentation pattern. They did not, however, report the isolation of a single pentamantane or hexamantane. Nor were they able to separate non-ionized components during their spectral analysis. McKervey et al. discuss an extremely low-yielding synthesis of anti-tetramantane.3 The procedure involves complex starting materials and employs drastic reaction conditions (e.g., gas phase on platinum at 360° C.). Although one isomer of tetramantane, i.e., anti-, has been synthesized through a double homologation route, these syntheses are quite complex reactions with large organic molecules in the gas phase and have not led to the successful synthesis of other tetramantanes. Similar attempts using preferred ring starting materials in accordance with the homologation route, have likewise failed in the synthesis of pentamantanes. Likewise, attempts using carbocation rearrangement routes employing Lewis acid catalysts, useful in synthesizing triamantane and lower diamondoids, have been unsuccessful in synthesizing tetramantanes or pentamantanes. Attempts to synthesize hexamantanes have also failed.
Among other properties, diamondoids have by far the most thermodynamically stable structures of all possible hydrocarbons that possess their molecular formulas due to the fact that diamondoids have the same internal “crystalline lattice” structure as diamonds. It is well established that diamonds exhibit extremely high tensile strength, extremely low chemical reactivity, electrical resistivity greater than aluminum oxide (alumina, or Al2O3), excellent thermal conductivity, a low coefficient of friction, and high x-ray transmissivity.
In addition, based on theoretical considerations, cyclohexamantane has a size in the nanometer range and, in view of the properties noted above, the inventors contemplate that such a compound would have utility in micro- and molecular-electronics and nanotechnology applications. In particular, the rigidity, strength, stability, variety of structural forms and multiple attachment sites shown by this molecule makes possible accurate construction of robust, durable, precision devices with nanometer dimensions. The various hexamantanes are three-dimensional nanometer sized units showing different diamond lattice arrangements. This translates into a variety of rigid shapes and sizes for the thirty-nine hexamantanes. For example, [12121] hexamantane is rod shaped, [121(3)4] hexamantane has a “T” shaped structure while [12134] is “L” shaped and [1(2)3(1)2] is flat with four lobes. The two enantiomers of [12131] have left and right handed screw like structures. Cyclohexamantane ([12312] hexamantane) is disc- or wheel-shaped.
It has been estimated that MicroElectroMechanical Systems (MEMS) constructed out of diamond should last 10,000 times longer then current polysilicon MEMS, and diamond is chemically benign and would not promote allergic reactions in biomedical applications.6 Again, the inventors contemplate that cyclohexamantane would have similar attractive properties. Applications of cyclohexamantane include molecular electronics, photonics, nanomechanical devices, and nanostructured polymers and other materials.
Notwithstanding these advantages of hexamantanes in general and cyclohexamantane in particular, the art, as noted above, fails to provide compositions comprising cyclohexamantane, or processes that would lead to these compositions. In view of the above, there is an ongoing need in the art to provide compositions comprising the C26H30 hexamantane herein referred to as cyclohexamantane.